In an ideal world maybe you wouldn’t have to worry about disk space. Hard drives would be inexpensive, reliable, and plentiful, and you could just store files endlessly without worry. I’d certainly enjoy that. The reality, of course, is that good storage costs real money, and allocation matters.

Last week we implemented hard disk quotas on our UNIX web servers. We’ve always had disk quotas, of course, but they were entirely managed by the FTP server. Because of this, non-FTP processes (primarily CGI and PHP scripts) could write files in excess of the disk quota and potentially cause problems.

Disk quotas are now hard limits managed by the file server itself. This protects the system from rogue processes filling the disk and thus protects the websites we host. However, it also means that you’ll want to pay attention to your disk usage, especially if you have processes which need to be able to write files to your website.

If you have a website on our UNIX web cluster then you can check your disk usage in one of two ways. First, through the web host control panel running at Login using your FTP username and password.

Second, if you’re comfortable with a UNIX command line, by logging into via SSH and running the command ‘quota -s’. The first triplet of numbers is your disk usage and quota, the second is the number of files and quota. Disk usage values are in kilobytes unless indicated otherwise, 100M means 100 megabytes.